The EvTimer class

(PECL ev >= 0.2.0)

Introduzione

EvTimer
watchers are simple relative timers that generate an event after a given
time, and optionally repeating in regular intervals after that.

The timers are based on real time, that is, if one registers an event that
times out after an hour and resets the system clock to
January last year
, it will still time out after(roughly) one hour. "Roughly" because
detecting time jumps is hard, and some inaccuracies are unavoidable.

The callback is guaranteed to be invoked only after its timeout has passed
(not at, so on systems with very low-resolution clocks this might
introduce a small delay). If multiple timers become ready during the same
loop iteration then the ones with earlier time-out values are invoked
before ones of the same priority with later time-out values (but this is
no longer true when a callback calls
EvLoop::run()
recursively).

The timer itself will do a best-effort at avoiding drift, that is, if a
timer is configured to trigger every
10
seconds, then it will normally trigger at exactly
10
second intervals. If, however, the script cannot keep up with the timer
because it takes longer than those
10
seconds to do) the timer will not fire more than once per event loop
iteration.

Proprietà

repeat

If repeat is
0.0
, then it will automatically be stopped once the timeout is reached. If
it is positive, then the timer will automatically be configured to
trigger again every repeat seconds later, until stopped manually.

remaining

Returns the remaining time until a timer fires. If the timer is active,
then this time is relative to the current event loop time, otherwise
it's the timeout value currently configured.

That is, after instanciating an
EvTimer
with an
after
value of
5.0
and
repeat
value of
7.0
,
remaining
returns
5.0
. When the timer is started and one second passes,
remaining
will return
4.0
. When the timer expires and is restarted, it will return roughly
7.0
(likely slightly less as callback invocation takes some time too), and
so on.